A non-regular reflection type holographic mirror which can reduce, when mounted as a reflection plate on a windshield of a vehicle, the inclination of a display image visually discerned by reflection and a process of manufacturing the same. The holographic mirror comprises a hologram plate including a transparent support member and a photosensitive agent layer formed on the transparent support member and having interference fringes formed therein such that the hologram plate has a function of a concave mirror at a first portion of the hologram plate and another function of a convex mirror at a second portion of the hologram plate on opposite sides of a horizontal center line. A reflection type display apparatus for a vehicle employing a non-regular reflection type hologram or a regular reflection type hologram constituting a concave mirror as a hologram combiner wherein a virtual image of a display unit is reversed into an erect image and compensated for in contraction to improve the discernibility.